Nano vs. Bio

An interesting article written by Prof. Ritchie presents some insights on the Nano and Bio inspired research in engineering. To quote "Shrinking the structure of a material to nanoscale dimensions certainly will increase the strength, but few of our advanced structural materials are ‘strength challenged’. On the contrary, they are invariably lacking in toughness. And, if nanostructured materials have one thing in common, it’s poor toughness!". This is actually true, I know it first hand. He says, the bio revolution is more encouraging compared to the nano revolution. An important piece of advice I got from my interaction with people in AM is that don't focus your learning on micro or nano, learn the fundamentals of AM, i.e., the physics underlying the behaviour of matter. And treat all the other stuff that we do as an application of these fundamentals.

I remember reading this article by Dr.Lawn (a renowned expert on fracture in Brittle Materials) on scaling. In conclusion after indentation based fracture investigation he says that toughness increases with decreasing scale. Which is contrary to what has been shown for several materials. However, from the experimental results presented one would come to the conclusion made by him. This brings up a point on testing methods used a various scales. It is not always true that experiments at the macro scale could be shrinked down to the micro and nano scale since the experiments inherently possess some critical assumptions which may not be indenpendent of length scale. Just my two cents...

Looks like our much hyped nano world will come to an end soon :(, I hope it waits until I graduate...